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Why is electricity billed in kilowatt hours?

This is my second electricity-related question tonight and I’m probably the only person in the world who has ever wondered this.  “Kilowatt hour” is a unit of energy but it’s redundant.  The unit for energy is the joule.  The kilowatt measures power, which is energy divided by time, but a kilowatt hour is energy divided by time then multiplied by time so time drops out and energy is all that’s left.  So, why not cut out the middleman and just bill electricity in joules instead of kilowatt hours?

Posted - November 16, 2023


  • 44393
    The KW-hr is a convenient term for billing and is fairly easy to understand. Most folks don't know what a Joule is.
      November 17, 2023 11:50 AM MST

  • 1452
    Petti and you complement each other so very nicely.
      November 17, 2023 6:33 PM MST

  • 33154
    One kilowatt-hour is the use of 1000 watts for 1 hour, or rather 1000 joules/second for 3600 seconds or rather 3.6 mega joules. (3,600,000 juoles)

    Kwh is just simpler. 
      November 18, 2023 5:30 AM MST

  • 3694
    It's simpler not just because the numbers are smaller, but it also relates directly to the power and running-time of the appliances and lights.
      December 3, 2023 4:03 PM MST